The chest x-ray shows a dilated gastric pouch underneath the left hemi diaphragm. There is a lap band visible which seems to have slipped.
This patient had further investigations which confirmed a slipped lap band with distension of the proximal gastric pouch all the way up to distal third of the oesophagus.
A lap band on a frontal chest/upper abdominal x-ray should have 2 important features:
- Phi angle between 4-58 degree. Phi angle is where the vertical axis of the spine meets the longitudinal axis of the lap band (reference attached for further reading).
- A lap band should have a rectangular appearance due to superimposition of the anterior and the posterior aspects.
Further reading: https://pubs.rsna.org/doi/full/10.1148/rg.324115177